N-nitroso derivatives



United States Patent 0" r 3,251,875 N-NITROSO DERIVATIVES Henry J. Gerjovich and Jean Bradley Harrison, Wilmington, Del., assignors to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed Aug. 31, 1962, Ser. No. 220,851 5 Claims. (Cl. 260-4655) This application is a continuation-in-part of our copending application Serial No. 107,341, filed May 3, 1961, now abandoned.

This invention relates to N-nitroso compounds and their use as plant growth regulants.

The novel compounds of this invention are represented by the following formula:

R is an unsubstituted straight chain hydrocarbon radical of less than 4 carbons, a hydroxy substituted straight chain hydrocarbon radical of less than 4 carbons or a halogen substituted straight chain hydrocarbon radical of less than 4 carbons and with the limitation that R must contain 2 or 3 carbon atoms when A is cyano;

X is oxygen or sulfur; and

R is hydrogen, alkyl of less than 7 carbons; alkali metal ion including lithium, sodium, potassium, rubidium and cesium; alkaline earth metal ion including magnesium, barium, strontium, and calcium; ammonium, monoalkylammonium, dialkylammonium, mono(alkoxyalkyl)ammonium, di(-alkoxyalkyl)ammo nium, -tri(alkoxyalkyl)ammonium, mono(alkoXyalkyl)- alkylammonium, or di(alkoxyalkyl)alkylammonium where alkoxyalkyl is less than 7 carbons and alkylammonium is less than 5 carbons, mono--, diand tri-alkanol ammonium, monoalkanol-dialkyl ammonium, monoalkanol-monoalkyl ammonium, dialkano'l-monoalkyl ammonium, and tetra-alkylammonium where each alkanol is 2 through 4 carbon atoms and each alkyl is 1 through 4 carbon atoms. 1

Specifically included within the scope of R can be mentioned straight chain alkyl of less than 4 carbons; monohydroxyalkyl of less than 4 carbons; dihydroxyalkyl of less than 4 carbons; haloalkyl of less than 4 carbons where halo includes chlorine, bromine, iodine and fluorine; allyl; haloallyl where halo includes chlorine, bromine, iodine and fluorine; propargyl and omega-halopropargyl where halo includes chlorine, bromine, iodine and fluorine.

Preferred compounds of this invention are N-nitroso- N-methyl-fi-alanines and N-nitroso-N-ethyl-B-alanines of the above formula where R, is hydrogen, alkyl, sodium, monoalkylammonium, dialkylammonium, trialkylammonium, mono-, diand tri-alkanolammonium, monoalkanol-monoalkylammom'um, monoalkanol-dialkylammonium, dialkanol-monoalkylammonium and tetra-alkylammonium, where each alkyl is 1 through 4 carbon atoms and each. alkanol is 2 through 4 carbon atoms.

Particularly preferred because of their outstanding effect as plant growth. control agents are the compounds of the structure:

wherein R is hydrogen, alkyl, sodium, monoalkylammonium,

or trialkylammonium,

3,251,875 Patented May 17, 1966 ice (a) NITROSATION OF THE AMINE Where R =H and X=O and Where R =alky1 and X=O or S, the nitroso compound is obtained by nitro- 55 These amines A, C, E are prepared by known methods. For example, type A amines are prepared by hydrolysis of amines C.

The type C amines areconveniently prepared by the addition of primary alkyl amines to the appropriate acrylic acid ester according to known methods [R. W. Holley, J.Am. Chem. Soc. 71, 2127 (1949)].

The type B amines are prepared in analogous fashion from primary alkyl amines and the appropriate thiolacrylic acid alkyl esters.

VII

The thiolacrylic acid esters CH =CHC-S-R where R =alkyl are prepared according to known methods [6. Brande, J. Org. Chem. 22, 1675 (1957)].

The type B amines are prepared from the primary amines and acrylonitrile according to well known literature methods [The Chemistry of Acrylonitrile, 2nd Ed. p. 23, copyright 1959 by American Cyanamid 00.].

Partial hydrolysis of E amines yields the E amides.

Compounds of the type r where X=O and R =H or alkyl or where X=S and R -'alkyl and where R contains a hydroxy or halosubstitution are made by n-itrosating the corresponding amine or amine salts. These amines are prepared by known methods. Some examples of these amines and their preparation are as follows:

lHCl

Ho-om-o Hz-OHz-NH: l 0 -0 112-0 H2C H2NHC H2OH2( iOH Compounds of the type R-N-C Hr-C Ha-O N rim are prepared by nitrosating the corresponding amines according to reaction III. Some examples of these amines and their preparation are as follows:

lHONO lHONO are prepared by nitrosating the corresponding amine according to reaction III".

(9) O It-NH; CHz=CH- NHz RNHGH CH (iNHz lHONO alkylammonium, and tetraalkylammonium where each alkanol is 2 through 4 carbons and each alkyl is 1 through 4 carbonatoms, and where n=1 or 2 to balance the valence of M are conveniently prepared by neutralization of the N-nitroso-N-alkyl-B-alanine with the appropriate base [ammonia, mono-, dior trialkylamine, alkali hydroxide, alkaline earth hydroxide, mono(alkoxy alky1)amine, di(alkoxyalkyl)amine, tn'(alkoxyalkyl) amine, mono(alkoxyalkyl)alkylamine, di(alkoxyalkyl) alkylamine where alkoxyalkyl is less than 7 carbon atoms and alkyl is less than 5 carbons; mono-, di-, and trialkanol amines where alkanol is 2 through 4 carbon atoms; monoalkanol-dialkylamine, monoalkanol-monoalkylamine and dialkanol-monoalkylamine; tetraalkylammonium hydroxide].

R =H or alkyl .(N) M+=alka1i metal ion The conversion of dialkylamines to N-nitrosodialkylamines Since these N-alkyl-beta-alanines (compounds A) are generally water soluble, water is the solvent of choice for this reaction. Other solvents (lower alcohols, acetic acid) as well as solvent mixtures (alcohol/water, acetic acid/water, dioxane/water, methylene chloride/water,

ethyl ether/Water) can :be used. The source of mtrous acid is conveniently sodium nitrite or potassium nitrite and a mineral acid (hydrochloric acid, sulfuric acid, or phosphorous acids). This generation of nitrous acid forms .a salt (for example sodium chloride) as .a byproduct.

The product N-nitroso-N-alkyl-beta-alanine (compound B) has an appreciable water solubility. Saturation of an aqueous solution of B with a salt such as sodium chloride .often precipitates the compound, generally as a yellow oil. If the nitrosation reaction is run under concentrated conditions such that the water solvent is nearly saturated with the by-product salt formed, then the reaction product B will often precipitate with no further added salt. The addition of an immiscible organic phase (for example methylene chloride or ethyl ether) before or after the reaction will aid in extracting the product B. The N-nitroso-N-alkyl-fl-alanine (B) is recovered from the water immiscible solvent by evaporation.

Since the nitrous acid is subject to air oxidation with formation of nitrogen dioxide, it is convenient to run the reaction in an inert atmosphere (for example nitrogen).

In a typical preparation one part by Weight of the amine (A) is dissolved in 1-10 parts by weight of water (preferred 1.3l.5 parts by Weight). An equivalent amount of concentrated mineral acid is now added while chilling to maintain the temperature of 0-20". The amine salt forms and remains in solution, .for example, with hydrochloric acid.

This solution is maintained at O-40 (preferred temperature (1-10") and an equivalent amount of solid sodium nitrite is added over a 0-30 minute period. The nitrosation is accompanied by an evolution of heat which is ,not always evident under the reaction conditions used. Occasionally an induction period of up to 1 hour is obtained before nitrosation commences. It will be advantageous if desired to use a slight stoichiometric excess of mineral acid as this tends to eliminate the induction period.

The reverse addition, involving dissolving the sodium nitrite and the amine (A) in water and adding the mineral acid to this mixed solution, also gives a good yield of the N-nitroso-N-alkyl-(i-alanine (B).

These N-nitroso-N-alkyl-p-alanines (B), as described, frequently precipitate as yellow oils, under the concentrated reaction conditions. Several, however, notably N- nitroso-N-methyl-fl-alanine and N-nitroso-N-(hydroxyethyl)-fl-alanine are appreciably soluble in the aqueous phase and are isolated by continuous extraction with an immiscible organic phase, for example methylene chloride.

The N-nitroso-N-alkyl-B-alanines (B) are most gen erally yellow oils. They .are soluble in numerous organic solvents (for example ethyl ether, methylene chloride, benzene, ethyl alcohol) as Well as water. They are insoluble'in petroleum ether. These compounds cannot be .distilled at conventional vacuum pressures (for example 0.5 to 10 mm. Hg) as extensive decomposition occurs.

The N-nitroso-N-alkyl-fi-alanine esters (compound D) and N-nitroso-N-alkyl-[i-alanine thiol esters (compound F) are prepared according to reactions II and HI above.

The source of nitrous acid is once again sodium (or potassium) nitrite and a mineral acid. The solvent can be water, a lower alcohol, acetic acid, or a mixture of solvents (methylene chloride/water, ethyl ether/water, alcohol-water, etc). A convenient method is to mix the amine (compounds C or E) with water and add an equivalent amount of mineral acid while chilling to maintain the temperature'in the range 30 (preferred 0-10). The starting amine (compound C or E) may be water soluble or water insoluble. The amine salt formed from the mineral acid generally will be water soluble, viz.:

An equivalent amount of solid sodium nitrite is added. Nitrous acid is formed and nitrosation takes place.

nitroso-N-alkyl-fiZ-alanine esters (compounds D) and the RNH2 O B-NH-C Hr-C Hz(J OH and/or HO-C H2C Hz-g NH-R This reaction frequently leads to mixtures of A and J. The N-alkyl-beta-alanines (compounds A) are frequently oils which cannot be purified by recrystallization. Where these N-alkyl-fi-alanines can be purified by recrystallization, notably N-ethyl-fl-alanine, mixtures of dimethylformamide and ethanol or dimethylformamide and water are extremely useful for recrystallizing purposes. The contamination, presumably N-ethylhydracrylamide (a compound of the type J), is removed thereby. Nitrosation of somewhat impure N-alkyl-fi alanines leads to mixtures with the desired N-nitroso-N-alkyl-,B-alanine as the major compound. The nature of the mixture is elucidated by a combination of elemental analysis, infrared analysis, and titration analysis. The oily N-nitroso-N- alkyl-fl-alanines all show a common characteristic infra- 8 red spectrum in the 2.9-4.5, 5.8-5.9, and -6.8-9.7,u re:

gions as follows:

Wave length: Nature of bands 2.9-4.5,u. Heavy sagging band with peak at 3.5 Infiection at 3.9,u. 5.8-5.9 Sharp carbonyl peak. 6.0-9.7;t Numerous sharp bands. (6.2-

The crystalline N-nitroso-N-alkyl-B-a1anines show a very similar spectrum with two notable difierences: The band at 3.5 is much sharper (less of a sag). The bands in the 6.9-9.7,u. region are more sharply defined.

This characteristic infrared spectrum of the pure oily N-alkyl-N-nitroso-B-alanines make possible the identification of N-alkyl-N-nitroso-fi-alanines (major component) in the presence of contaminants (such as N-alkyl-hydracrylamides). The percentage of N-nitroso-N-alkyl-fialanine is conveniently determined by titration.

It should be noted that the 'infrared spectrum of.

N-nitroso compounds has been described in the literature (J. Chem. Soc. 691, 1954) and bands at 7.1-7.4, 8.0, and 9.5,u attributed to the N-NO function.

The N-nitroso-N-alkyl-B-aminopropionitriles and the corresponding N-nitroso-N-alkyl-B-aminopropionic acid amides are prepared from amines E and E" according to reaction In and III" above.

The compounds of this invention have outstanding utilityas plant growth control agents. They control the.

flowering and fruiting of a wide variety of plants, both broadleaves and grasses including for example, alfalfa, clover, beans, tobacco, marigold, chrysanthemu'm, buckwheat, crabgrass, bluegrass and other forage grasses, and fruit trees.

These compounds exert plant growth retardant action on ornamental shrubs (forsythia, yews, privet, for example), grasses (such as bluegrass, bentgrass, fescue, quackgrass, Johnsongrass, wild oats, Bermudagrass, ryegrass, and foxtail), and broadleaf plants (for example, chickweed, mustard, bindweed, Zinnia, and numerous leguminous plants).

Axillary stimulation is initiated on ornamental shrubs.

a the dominance of the upper axillary bud on tobacco plants after tobacco has been topped (terminal bud removed).

An especially important advantage of this invention is the stimulation of stooling or, tillering, i.e., increased number of growth stemsfrom one root stock on desirable grass and small grain species. Important results therefore from treatment with the present compounds are the retardation of grass growth with reduction in mowings and the creation of a thicker, more desirable turf.

The compounds of this invention can be applied aspreemergence or post-emergence applications, soil drenches, or they can be mixed intimately with the soil. Rates of application will usually be in. the range of 0.25 to 16 pounds per acre. However, when these materials are mixed well with the soil, use rates can be higher.

The compound can be applied in any of a variety of compositions. Thus, those that are sufiiciently water soluble can be applied simply in water solution. It is preferred, however, that the compounds be extended with a carrier material or conditioning agent.

Particularly beneficial plant growth regulant compositions are those of the following novel and useful compositions:

(1) From 25 to 97% by weight of at least one compound of this invention in admixture with from 3 to 75% by weight of inert solid powder having an average particle size below about 50 microns;

(2) From 0.5 to' 50% by weight of at least one compound of this invention in an emulsifiable oil; and

(3) From 5 to 90% by weight of at least one compound of this invention with up to about 15% by weight of a surface active agent.

either can be used as such, diluted with inert solids to form dusts, or suspended in a suitable liquid medium for spray application. The powders usually comprise active ingredient admixed with minor amounts of conditioning agent. Natural clays (either absorptive such as attapulgite or relatively non-absorptive such as china clay), diatomaceous earth, walnut shell flour, redwood flour, synthetic fine silica, calcium silicate and other inert solid carriers of the kind conventionally employed in powder fungicidal compositions can be used. The active ingredient usually makes up from about 25.97% of these powders compositions. The solids ordinarily are very finely divided and have a particle size below about 50 microns and preferably below about microns. For conversion of the powders to dusts talc, pyrophyllite, tobacco dust, volcanic ash and other dense, rapid-settling inert solids customarily are used.

If the active compound used is water soluble, it can be sprayed onto or in any other desired manner applied to an absorptive powder, or granules made from such powders, which can then be dried to produce a dry product. Any of the above absorptive materials can be used for the preparation of such products.

Liquid compositions including the active compounds above described can be prepared by admixing the compound with a suitable liquid diluent medium. The active compound can be either in solution or in suspension in the liquid medium. Typical of the liquid media commonly employed are kerosene, Stoddard solvent, xylene, alkylated naphthalene, glycols and ketones such as diisobutyl ketone, cyclohexanone, etc. The active ingredientusually makes up from about 0.5 to of these liquid compositions. Some of these compositions are designed to be used as such, and others to be extended with large quantities of water.

Compositions in the form of wettable powders .or liquids can also include one or more surface-active agents such as wetting, dispersing or emulsifying agents. Thus, mixtures of the above liquids with the active compounds can contain an emulsifying agent to make an emulsifiable oil composition. The surface-active agents cause the liquid or dry compositions to disperse or emulsify easily in water to give aqueous sprays.

The surface active agents employed can be of the cationic, or preferably the anionic or nonionic type. They include, for example, sodium oleate, sulfonated petroleum oils, alkyl aryl sulfonates, sodium lauryl sulfate, polyethylene oxides, lignin sulfonates, and other surface-active agents. A detailed list of such agents is set forth in a book by John W. McCutcheon, Inc., Detergents and Emulsifiers-Up to Date (1962) and Bulletin E-607 of the Bureau of Entomology and Plant Quarantine of the U.S. Department of Agriculture.

The compounds can be applied in compositions of the type shown in Jones U.S. Patent 2,412,510 in which an active compound of the invention replaces the active materials of that patent in the composition shown and in like amounts. Similarly, any of the carriers, additives or surface-active agents there named or referred to can be used. The entire disclosure of the aforesaid Jones patent is hereby incorporated herein. a

In order that the invention may be better understood, the following illustrative examples are given in addition to those above. All percentages are by weight unless otherwise indicated.

Example 1 STEP 1 To a solution of 72 parts by weight of 8-propiolactone in 500 parts by weight of acetonitrile is added 45.2 parts by weight of ethyl amine over a period of /2 hour. The reaction is exothermic and cooling is required to maintain the temperature at 22-33". A heavy White precipitation occurs during the course of the addition. For /2 hour after completing the addition the reaction mixture continues to evolve heat. Thereafter no further heat evolution is noted and the reaction mixture is stirred at room temperature for 20 hours. The white crystalline product is filtered, washed with acetonitrile, and dried. The yield is 108 parts by weight, M.P. 162-166. This product is stirred with 980 parts by weight of N,N- dimethylformamide at 70-90" while parts by weight of ethyl alcohol is added. A clear solution is obtained. On cooling essentially pure N-ethyl-fi-alanine separates out as white crystals. These are filtered, washed with dimethyl formamide/ethanol, and dried. The yield is 82 parts by weight, M.P. 174176'.

Analysis.C H NO C, 51.3; H, 9.46; N, Found: C, 50.39; H, 9.26; N, 11.78.

STEP 2 To 10.0 parts by weight of N-ethyl-fi-alanine in 15 parts by weight of water is added 8.8 parts by weight of concentrated hydrochloric acid while chilling to maintain temperature at 10-17 Now 5.9 parts by weight of solid sodium nitrite is added portionwise over a 23-minute period while chilling to maintain temperature at 4-8. The reaction mixture turns lime green and becomes turbid. The reaction mixture is now allowed to come to room temperature and stirred for twenty hours. A good yield of yellow 'oil forms during this period. The yellow oil is taken up in '40 parts by weight of methylene chloride. Evaporation of the methylene chloride solution gives essentially pure N-nitroso-N-ethyl-,B-alanine as a yellow oil. The yield is 9.8 parts by weight.

Analysis.'C H N O C, 41.1; H, 6.89; N, 19.2. Found: C, 41.28; H, 7.10; N, 18.60.

This oily N-nitroso-N-ethyl- -alanine shows the following infrared peaks:

2.9-4.5, Heavy sagging band with peaks at 3.4 and shoulder at 3.9. 5.8;]. Strong band. 6.95;, 7.2 1., 7.5 8.2/1. Series of peaks not sharply differentiated. 9.3 Sharp peak.

This compound is formulated into a water soluble formulation according to the following recipe:

Percent N-nitroso-N-ethyl-fi-alanine 25 Alkyl naphthalene sulfonic acid, Na salt 0.5 Sodium lignin sulfonate 1.0 Attapulgite clay 73.5

The above components are combined by first blending the surfactants and the clay and then spraying in thesyrup is readily water soluble.

these plants at the size desired. One to two such treatments per year maintains the omamentals at the desired size.

Example 2 STEP 1 To a solution of 72 parts by weight of fi-propiolactone in 500 parts by weight of acetonitrile is added gradually 31 parts by weight of methylamine. The addition takes 1 hour. The reaction is markedly exothermic and is maintained at 24-32 with cooling, During the addition a white syrup precipitates. Following the addition the reaction mixture shows little or no further tendency to heat up. The heavy white syrup is present as a lower phase. The acetonitrile upper phase is decanted off. The sticky white syrup is washed with acetonitrile. This It is a mixture of N- methyl-fl-alanine and presumably N-methyl-hydracrylamide.

STEP 2 To 102 parts by weight of the white syrup dissolved in 110 parts by weight of water is added 99 parts by weight of concentrated hydrochloric acid while chilling to keep the reaction mixture at 20-30. To this solution is added 69 parts by weight of solid sodium nitrile while chilling to maintain the temperature at 4-11. The addition takes 20 minutes during which time the reaction mixtures become green colored. This reaction mixture is stirred for 20 hours, During this time the color changes from green to yellow. No precipitate forms. This aqueous solution is now exhaustively extracted with methylene chloride in a continuous liquid-liquid extractor. Evaporation of the methylene chloride extract yields 22 parts by weight of a yellow oil.

Analysis.C H N O3: C, 35.6; H, 6.09; N, 21.2; C1, nil; Neut. equiv., 132.1. Found: C, 38.6; H, 6.32; N, 19.02; Cl, 0.34; Neut. equiv., 149;

This reaction product is now formulated according to the following:

Percent N-nitroso-N-methyl-;3-alanine 50 Methyl Cellosolve 47 Isooctyl phenyl polyethoxy ethanol 3 The above liquid composition is prepared by simple mixing of the components. Upon dilution to use levels with water all components are soluble.

One to two pounds (active) of this material is dissolved in 60 gallons of water and sprayed on an acre of alfalfa, red clover, and ladino clover mixture before flower primodia are visible (when the crop is 16-10 inches tall). This treatment delays and often prevents flowering and seed production by the crop, thus allowing more vegetative growth. With this treatment, the yield of high quality forage is increased.

Example 3 14.6 parts by weight of N-nitroso-N-ethyl-p-alanine is stirred with 100 parts by weight of water to give an opaque lime-green solution. To this is added a solution of 4.0 parts by weight of sodium hydroxide in 40 parts by weight of water while cooling to maintain the temperature at 23-29". Vacuum evaporation of the Water solution yields 16.8 parts by weight of essentially pure N-nitroso-N-ethyl-fl-alanine sodium salt. This product melts over the range 194l98.

Analysis.C H N O Na: C, 35.7; H, 5.40; N, 16.7; Na, 13.7; Neut. equiv., 168.1. Found: C, 35.73; H, 5.68; N, 1'6.9;'Na, 13.5; Neut. equiv., 168.

This material is formulated as follows:

Percent N-nitroso-N-ethyl-B-alanine sodium salt 4 -30 mesh granular Attaclay 96 This product is prepared by spraying a concentrated aqueous solution of the active material upon granular "Attaclay while tumbling the latter, then drying.

One hundred twenty-five pounds per acre of the granular formulation is applied to bluegrass turf with a lawn spreader prior to the emergence of crabgrass. Crabgrass is retarded markedly. Fescue,,bentgrass and bluegrass show marked retardation of foliage growth. This reduces the number of mowings during the growing season.

the temperature at 1022.

' immediate oily precipitate forms.

- Example 4 24.7 parts by weight of N-ethyl-B-alanine methyl ester is stirred with 40 parts by Weight of water to give a clear solution. To this is added 19 parts by weight of concentrated hydrochloric acid while cooling to maintain Now 13.0 parts by weight of solid sodium nitrite is added over a 2-3 minute period while chilling to kep the reaction mixture at 27. An The reaction mixture is now stirred for 1 hour during which time it is allowed to come to room temperature. During this time the amount of yellow oil increases noticeably. The yellow oil is now taken up in methylene chloride. Evaporation of the methylene chloride solution yields 22 parts by weight of yellow oil. This oil is distilled in vacuo. The pure fraction distilling at 102-104/0.8 amounts to 16 grams. This is N-nitroso-N-ethyl=B-alanine methyl ester, a yellow oil. It is formulated and used as follows:

Percent N-nitroso-N-ethyl-B-alanine methyl ester 25 Polyoxyethylene sorbitan mono ester of tall oil acids 5 Xylene 70 Example 5 41 parts by weight of N-methyl-3-amino-thiolpropionic acid methyl ester is stirred with a mixture of 60 parts by weight of methyl alcohol and 22.0 parts by weight of sodium nitrite while adding gradually 23.4 parts by weight of concentrated hydrochloric acid. Chilling maintains the reaction temperature at 0-10 during the 15-minute. addition period. The reaction mixture .assumes a green and then a yellow color. After 2 hours stirring the reaction mixture is vacuum concentrated to a mixture of inorganic solids and yellow organic oil. This residue .is taken up in methylene chloride and filtered. Evaporation of the methylene chloride solution gives the essentially .pure yellow oil, N-nitroso-N-methyl- 3-amino-thiolpropionic acid methyl ester. It is formulated. according to the following recipe:

Percent N-nitroso-N-methyl-3-amino-thiolpropionic acid methyl ester 35 Polyoxyethylene lauryl ether 3 Synthetic fine silica 62 The surfactant is first mixed with the liquid active material then this mixture is sprayed upon the silica while blending. This is followed by micropulverizing and re- N-nitroso-N-ethyl-fl-alanine sodium salt is formulated on Attaclay as an compound: 20% Attaclay 'mix and then used on tobacco to prevent terminal bud V dominance and on beans to reduce flowering.

The water-soluble formulation is applied in 60 gallons of water at the rate of '1 pound (active) per acre to tobacco plants immediately after toping. The axillary buds extend and grow vigorously in the axils of all the tobacco leaves. This is unusual since the terminal axillary bud usually becomes dominant and prevents vigorous growth of the other axillary buds.

When this formulation is applied in 60 gallons of water to Black Valentine beans (first trifoliate leaf expending) at the rate of 0.25 pound (active) per acre, flower production is reduced by as much as 45% to 65% Plants are markedly shortened in height as compared to untreated plants.

Examples 7 and 8 N-nitroso-N-ethyl-B-alanine ethyl ester and N-nitroso- N-ethyl-fl-alanine isopropyl ester are prepared according to the procedures of Example 4 by substituting appropriate amounts of N-ethyl-B-alanine ethyl ester and N- ethyl-fi-alanine isopropyl ester for the 24.7 parts by weight of N-ethyl-B-alanine methyl ester of Example 4.

These product compounds can be formulated and used as emulsifiable oils according to Example 4 or as sandchemical mixes according to Example 5. The emulsifiable oils when mixed with water and applied at 6-10 113/ acre are active in retarding grasses. The sand-chemical mixes when mixed with potting soil inhibit leginess of chrysanthemums and poinsettias, and other plants.

Examples 9 and 10 N nitroso N (n propyl) B alanine and N- nitroso-N allyl-fi-alanine are prepared according to the general procedures of Examples 1 and 2.

EXAMPLE 9 40 parts by weight of fi-propiolactone in 234 parts by weight of acetonitrile is reacted with 32.9, parts by weight n-propylamine. A viscous organic oil separates. Itis separated and washed with acetoni-trile. This organic oil contains some dissolved acetonitrile After this solvent is removed under vacuum, the viscous yellow syrupy product amounts to 64.9 parts by weight. Titration analysis indicates it consists of 67% N-isopropyl-B-alanine and 23% N-isopropylhydracrylamide.

43.1 parts by Weight of'this. syrupy product is dissolved in. water. 34.2 parts by weight of concentrated hydrochloric aeid is added followed by 23.5 parts by weight of sodium nitrite. A yellow oil forms. It is isolated, and

the yield is 21.0 grams.

T hery.N, 17.5%; Neut. equiv, 160. Found: N,

16.43, 16.52; Neut. equiv., 180.

The data indicate that the product consists of 88% N- nitroso-N-(n-propyl) 8-alanine and 12% of a neutral impurity.

This yellow oily product can be formulated and used according to the procedures of Example 1.

EXAMPLE 1-0 55.7 parts by weight of p-propiolactone in. 3. parts by weight of acetonitrile is reacted with 44.1 parts by weight of allylamine. A white gummy precipitate forms. This precipitate crystallizes from 131- parts by weight of dimethylformamide and 23 parts by weight of water.

1 The product is 20 parts by weight of essentially pure N-allyl-B-alanine, M.P. 142147, a White crystalline solid.

Neut. equiv. Theory for C H NO 129 Found 130 18.5 parts by weight of the N-allyl-[i-alanine is dissolved in 50 parts by weight of water. 15.1 parts by Weight of concentrated hydrochloric acid is added followed by 10.1 parts by weight of sodium nitrite. A yellow oil precipitates and is isolated. The yield is 19.4 grams.

Neut. equiv. Theory for C H N O 158 Found 167 The titration analysis shows that the product is 88% N- nitroso-N-allyl-B-alanine mixed with 12% of a neutral impurity. This material can be formulated and used according to the procedures of Example 1.

Examples 11I6 The following N-nitroso-N-alkyl-B-alanine salts are prepared according to the procedures of Example 3 by substituting the N-alkyl-fi-alanine (and its parts by weight) in the table for the 14.6 parts by weight of N-ethyl-B- alanine used in Example 3 and by substituting the base (and its parts by weight) for the 4.0 parts by weight of sodium hydroxide used in Example 3.

TABLE I Example N-nitroswN-alkyl- Base Product N o. e-alaiune 11 N-nitroso-N- Dimethylamine N-nitroso-N-ethylethyl-B-alanine (4.50 parts). B-alanine di- (14.6 parts), ngfghyl amine 1 2 N nitroso- Tributylamine N-nitroso-N- methyl-fl- (18.5 parts). methyl-flalanine (13.2 alanine tributylparts). amine salt.

13 N-nitrosoN-(n- Ethylamine (4.5 N-nitroso-N-(n- D D Y )-B- p t p py ifialanine (15.5 alanine ethylparts). amine salt.

14 N-nitroso-N-allyl- Ammonia (1.20 N-nitroso-N-allylfi-alauine (15.3 parts). Balan ine ammoparts). nium salt.

15 N-nitroso-N- Barium hydrox- N-nitroso-N-ethylethyl-flalanine ide 81120 (31.5 B-alam'ne barium (14.6 parts). parts salt.

16 N-nitroso-N- Ethoxyethyl- N-nitroso-N- methyl-fiamine (8.91 methyl-B-alanine alanine (13.2 parts). ethoxyethyl parts). amine salt.

17-; N-nitroso- Ethanolamine N-nitroso-N-ethylethyl-B-alanine (6.1 parts). fl-alanine, ethna- (14.6 parts). olamine salt. 18 d0 N -n1ethyl-etha- N -nitroso-N ethylnolamine (7.5 fl-alanine salt parts). with N -methylethanolamine.

These N-nitroso-N-alkyl-fi-alanine salts of Examples 1 l-1-8 can be formulated and used as in Examples 3 and 6.

Examples 192I The following N-nitroso-N-alkyl-B-alanine esters are prepared according to the procedures of Example 4 by substituting the N alkyl-fl alanine ester (and. its parts by weight) for the 24.7 parts by weight of N-ethyl-fl-alanine methyl ester used in Example 4.

1 These N-nitroso-N-alkyl-fi-alanine esters-are i ormula'ted and used according to the procedures of Examples 1, 4 and 5.

Examples 22-24 The following N-nitroso-N-alkyl-B-aminothio1propi-onic acid esters are prepared according to the methods of Example 5 by substituting the N-alkyl-B-aminothiolpropionic acid esters and their parts by weight for the 41 parts by weight of N methyl-3 aminothiolpropionic acid methyl These N-nitroso-N-alkyl-B-aminothiolpropionic esters of Examples 212-24 can be formulated and used as described in Examples 4 and 5.

Example 25 N-nitroso-N-ethyl-fl-alanine, sodium salt, is applied at the rate of 4 pounds (active) per acre in 60 gallons of water to young barley plants (5 weeks after seedling or in late winter or early spring when vigorous growth begins). Within three to four weeks after treatment, the barley plants show an increase of 2 to 4 times the number of tillers (upright stems) as compared to untreated plants.

This is especially beneficial when a poor stand of barley is obtained and it is desirable to increase the number of 'tillers per acre. Similar results are obtained on wheat, oats and rye.

In the case of turf and roadside grasses, 4 pounds of active ingredient per acre applied during the growing season retards the growth of foliage and decreases the number of required mowings per season. Further, this treatment increases-the tillering of bluegrass, bentgrass, fescues, Johnson grass, and other turf and roadside grasses.

This results in a thicker stand of grass and give a more pleasing appearance to the viewer.

Example 26 To a solution of 1273 g. (13 mol) of fi-ethylami-nopropionitri'le in 1800 ml. of water is added 1250 ml. (l5 mol) of concentrated HCl with cooling. The solution is Iblanketed with a stream of N and is cooled to about C. Solid NaNO (1036 g.; 15 m.) is added slowly in portions, each portion being added as the foam subsides from the previous addition. The mixture is stirred .for a further period of 2 hours. One liter of methylene chloride is added and the lower organic layer is separated. "Ihe aqueous phase is extracted twice with 250 ml. of methylene chloride. The combined methylene chloride solutions are washed once with 250 ml. of saturated NaCl solutions. The methylene chloride is removed by distillation at atmospheric pressure and finally under reduced pressure at temperatures not greater, than 45 C. Finally, a small residual water content is removed at about 1 mm. Hg. and 45 C. The compound produced is N-nitroso-N-ethyl-fi-aminopropionitrile. Yield 1636 g. (99%) yellow, semi-viscous oil; n 1.4660; percent N, 32.77% (Dumas), theory 33l1%.

The compound made above is formulated as follows:

Percent N-nitroso-N-ethyl-fi-a-minopropionitrile 25.0 Dioctylsodium sulfosuccinate 0.3 Partially desulfonated sodium lignin sulfonate i 1.0 Attapulgite clay 73.7

The above wettahle powder is prepared by blending the components together, then micropu'lverizing to deagglomerate lumps and extend the liquid active material over the surfiace of the clay.

This formulation is applied at the rate of 4 to 8 pounds in 100 gallons of water to ornamentals to run-off. Such ornamentals as yews, forsythia and prive't show redulced growth. This reduces the amount of trimming needed to keep these plants at a desirable size.

Example 27 A solution of 115 parts by weight of 3-(2-hydroxyethylamino)propionitrile in 150 parts by weight of water is neutralized with concentrated hydrochloric acid. Sixtynine parts by weight of N-aNO- is added slowly at a temperature of 102() C. over a period of 40 minutes with a nitrogen blanket over the reaction mixture. After stirring for 5 hours at 25 C. the mixture is extracted with five successive 100 parts by weight portions of methylene chloride. The combined extracts are washed with parts by weight of saturatedNaCl solution. Solvent and residual water is removed under reduced pressure at 45 C. bath temperature. The compound produced is N-nitroso- N-(Z-hydroxyethyl) -fi-aminopropionitrile. Yield 129 parts by weight (90%).

Analysis.Percent N (Dumas), 29.0; theory 29.4.

The compound made above is formulated as follows:

Percent N-nitroso-N-(2hydroxyethyl)-fi-aminopropionitrile 25 Blend of polyoxyethylene ethers and oil soluble sulfonates 5 Xylene 70 The above mutually soluble components are mixed together to form a homogeneous emulsifiable solution.

An application of 6 to 10 pounds of active ingredient per acre of this material in gallons of water gives excellent retardation of :crabgrass, chickweed and wild oats growing around loading platforms.

Example 28 One hundred sixteen parts by weight of 3-ethylaminopropionamide is neutralized with hydrochloric acid in essentially the same manner as in Example 27. Sixty-nine parts by weight of NaNO is added in small portions over a period of two hours. Nitrosation of the amido group is avoided by maintainingthe temperature at 5-l0 C. The product isextracted with ether. The ether solution is washed with saturated NaCl solution and the solvent and residual Water removed under reduced pressure. The compound produced is N-nitroso-N-ethyl-B-aminopropionamide. Product: yellow oil, yield.

Analysis.Percent N 29.2%; theory, 28.9%.

The compound produced is formulated as follows:

7 Percent N-nitroso-N-ethyl-B-aminopropionamide 50.0 Nonyl phenol ethylene oxide adduct 2.0 Low' viscosity methyl cellulose 0.3 Synthetic fine calcium silicate 47.7

The above components are blended and micropulv'erized until substantially all particles are below 50 microns.

The above formulation is applied at the rate .of 6-10 pounds of active ingredient in 100 gallons of water per acre to roadside grasses, which have been recently mowed. Subsequently, a marked reduction in rate of growth is noted on such grass species as Johnson grass, crabgrass, foxtail and bluegrass.

Example 29 Percent N-nitroso-N-propyl-B-aminopropionamide 10 Ammonium sulfate The above components are ground together then moist granulated and dried to yield 15-60 mesh granules.

This formulation is applied at the rate of 4 to 8 pounds of active ingredient per acre with a granular applicator to a roadside area planted to Kentucky 31 fescue turf. This applicationwhen applied prior to germination of crabgrass and chickweed gives excellent retardation .of these two plants.

Examples 30-79 The following compounds are each substituted one at a time for the N-nitroso-N-propyl-B-aminopropionamide of Example29 in like amount by weight and are formulated and applied in like manner. Like results are obtained.

Example:

. N-nitroso-N-methyl-fl-alanine N-nitroso-N-ethyl-B-alanine N-nitroso-N-(n-propyD-B-alanine N-nitroso-N-allyl-fl-alanine N-nitroso-N-propargyl-fi-alanine N-nitroso-N-(Z-chIoroethyD-B-alanine N-nitroso-N-(2-hydroxyethyl)-;8-alanine N-nitroso-N-ethyl-3-amino-thiolpropionic acid N-nitroso-N-methyl-fi-alanine methyl ester N-nitroso-N-ethyl-B-alanine ethyl ester N-nitroso-N-(n-propyl)-B-alanine n-propyl ester N-nitroso-N-methyl-fi-alanine n-butyl ester N-nitroso-N-ethyl-fi-alanine amyl ester N-nitroso-N-propyl-fi-alanine hexyl ester N-nitroso-N-ethyl-3-amino-thiolpropionic acid ethyl ester 45. N-nitroso-N-methyl-3-amino-thiolpropionic acid ethyl ester 46. N-nitroso-N-ethyl-fi-alanine sodium salt 47. N-nitroso-N-ethyl-B-alanine N-methylammonium salt 48. N-nitroso-N-ethyl-B-alanine N,N-dimethylammonium salt 49. N-nitroso-N-methyl-;8-alanine N,N,N-trimethylammonium salt 50. N-nitroso-N-ethyl- -alanine barium salt 51. N-nitroso-N-ethyl-fi-alanine ethoxyethylamine salt 52. N-nitroso-N-ethyl-B-alanine salt with N,N-

dimethyl-B-butoxy ethylarnine salt 53. N-nitroso-N-ethyl-3-amino-thiolpropionic acid sodium salt 54. N-nitroso-N-(2,3-dihydroxy-n-propyl)-13- alanine lithium salt 55. N-nitroso-N-methyl-B-alanine beryllium salt 56. N-n-itroso-N-(3-iodoallyl)-B-alanine cesium salt 57; N-nitroso-N-trifluoromethyl-[3-alanine N,N,N-

tributylammonium salt 58. N-nitroso-N-ethyl-fi-alanine N,N,N,N-tetrabutyl ammonium salt 59. N-nitroso-Nethyl-B-alanine N,N,N,N-tetraethyl ammonium salt 60. N-nitroso-Nethyl-fl-alanine, N,N-di(fi-ethanol) ammonium salt 61. N-nitroso-N-ethyl-B-alanine N,N,N-tn'(flethanol)ammonium salt 62. N-nitroso-N-ethyl-fi-alanine N,N-dimethyl-N- (fl-ethanonammonium salt 63. N-nitroso-N-ethyl--alanine-N methyl-N,N-di- (B-ethanoDammonium salt 64. N-nitroso-N-ethyl-B-alanine, ethanolamine salt 65. N-nitroso-N-ethyl-fl-alanine, N-methyl-ethylamine salt 66. N-nitroso-N-bromoethyl-B-aminopropionitrile 67. N-nitroso-N-ethyl-fi-aminopropionitrile 68. N-nitroso-N-(propyl)-B-aminopropionit1ile 69. N-nitroso-N-(2-hydroxyethyl) -fl-amino propionitrile 70. N-nitroso-N-(3-chloropropyl)-1S-aminopropionitrile 71. N-nitroso-N-methyl- 3-aminopropionamide '72. N-nitroso-N-ethyl- -aminopropionamide 73. N-nitroso-N-propyl-fl-aminopropionamide 74. N-nitroso-N-(2:hydroxyethyl)-B-arninopropionamide 75. N-nitroso-N-(Z-ehloroethyl)- 8-aminopropionamide 76. 2-hydroxyethylammonium salt of N-nitroso-N- ethyl-B-alanine 77. N-methyl-(Z-hydroxyethylammonium) salt of N-nitroso-N-ethyl-fl-alanine 78. N',N'-dimethyl-(Z-hydroxyethylammonium) salt of N-nitroso-N-ethyl-fl-alanine 79. N'-methyl-(Z-hydroxypropylammonium) salt of N-nitroso-N-ethyLfl-alanine Example A solution of 84 parts by weight of fl-n-propylaminopropionitrile in .200 parts by weight of water is neutralized with an excess of concentrated hydrochloric acid (75 parts by weight). To the acidic solution maintained at 1015 C. is added 63 parts by weight of solid NaNO in portions while the reaction mixture is blanketed with N to prevent the reaction of evolved NO with 0 of the air. A second liquid phase appears as the NaNO addition nears completion. The mixture is stirred overnight and the organic phase is separated, washed with parts by weight of saturated NaCl solution and then dried under reduced pressure at 45 C. to produce a yellow oil. This compound is N-nitroso-N-propyl-fl-aminopropionitr-ile. Yield 104 g., 99%, n 1.4650, percent N (Dumas) 29.12%, theory 29.8%.

It will be readily understood by persons skilled in the art from a reading of the above exemplary disclosure that other products within the scope of this invention can be prepared and used in accordance with the teachings hereinby simple substitution of appropriate materials in the above examples which are given for purposes of illustration only.

The invention claimed is:

1. A compound of the formula:

RNC H2C H2A 0 wherein A is selected from the group consisting of R is selected from the group consisting of an unsubstituted straight chain hydrocarbon radical of 1 through 3 carbons, a hydroxy substituted straight chain hydrocarbon radical of 1 through 3 carbons, a halogen substituted straight chain hydrocarbon radical of 1 through 3 carbons and with the limitation that R must be 2 through 3 carbon atoms when A is cyano;

X is selected from the group consisting of oxygen and sulfur and R is selected from the group consisting of hydrogen,

alkyl of 1 through 6 carbons, alkali metal ion, alkaline earth metal ion, ammonium, mono-alkylammonium, dialkylammonium, trialkylammonium, mono-, di-, and tri-alkanolammonium, monoalkanoldialkylammonium, monoalkanol-monoalkylammonium, dialkanol-monoalkylammonium and tetra alkylammonium, where each alkyl is 1 through 4 carbons and each alkanol is 2 through 4 carbon atoms, mono alkoxyalkyl ammonium, di alkoxyalkyl ammonium, tri(alkoxyalkyl)ammonium, mono(alkoxyalkyl) alkylammonium, and di(alkoxyalkyl)alkylammonium where alkoxyalkyl is 1 through 6 carbons and alkylammonium is 1 through 4 carbons.

2. N-nitroso-N-ethyl-B-aminopropionitrile.

3. N-nitroso-N-ethyl-/3-aminopropionarnide.

4. N-nitroso-N-ethyl-B-alanine.

5. N-nitroso-N-ethyl-fi-alanine, N,N-d imethyl ammoni- 3,068,274 12/1962 McCall 260-465.5

um salt. 3,096,362 7/1963 Sexton 260-4655 References Cited by the Examiner OTHER REFERENCES UNITED STATES PATENTS 5 Kissinger et aL; CA, 53 (1959), p. 15968e.

2,852,553 9/1958 DAmico et a1. 260471 Tafel et 3 (1909) 2,892,6.96 6/1959 Barrons 712.7 3,009,854 11/1961 Russell 260482 X LORRAINE A. WEINBERGER, Prlmary Examine). 3,031,492 4/1962 Frankel et a1. 260482 JULIAN S. LEVITT, CHARLES B. PARKER,

3,054,667 9/1962 Josephs 71--2.7 10 Examiners. 

1. A COMPOUND OF THE FORMULA: 